EP 0140567 B1 19911023 - APPARATUS FOR CONTROLLING THE FREQUENCY OF A VOLTAGE CONTROLLED OSCILLATOR
Title (en)
APPARATUS FOR CONTROLLING THE FREQUENCY OF A VOLTAGE CONTROLLED OSCILLATOR
Publication
Application
Priority
- JP 17477783 A 19830921
- JP 17477883 A 19830921
Abstract (en)
[origin: EP0140567A2] In an automatic frequency control (AFC) circuit (10) of a video tape recorder, a charge pump circuit (13, 14) is used to form a control signal for a voltage controlled oscillator (VCO) 5 included in the AFC circuit by phase-comparing (12) a horizontal synchronising signal (HSYNC) from a video signal with an output of the VCO 5. An AFC-identification circuit (24) can be added to the AFC circuit (10) to make locking-in of the circuit (10) smooth and fast when the AFC circuit is out of a lock-in range.
IPC 1-7
IPC 8 full level
H03L 7/10 (2006.01)
CPC (source: EP KR US)
H03L 7/08 (2013.01 - KR); H03L 7/10 (2013.01 - EP KR US); H04N 5/05 (2013.01 - KR)
Designated contracting state (EPC)
AT DE FR GB NL
DOCDB simple family (publication)
EP 0140567 A2 19850508; EP 0140567 A3 19870805; EP 0140567 B1 19911023; CA 1238409 A 19880621; DE 3485208 D1 19911128; KR 850002364 A 19850510; KR 920006945 B1 19920822; US 4630000 A 19861216
DOCDB simple family (application)
EP 84306429 A 19840920; CA 463544 A 19840919; DE 3485208 T 19840920; KR 840005793 A 19840921; US 65209484 A 19840919